1. Field of the Invention
An embodiment of the present invention relates to a solid-state imaging device including a photosensor in a pixel, and to a semiconductor display device including a photosensor and a display element in a pixel.
2. Description of the Related Art
A photosensor utilizing an amplifying function of a MOS transistor, called a CMOS sensor, can be manufactured by a general CMOS process. Thus, manufacturing cost of a solid-state imaging device including a CMOS sensor in each pixel can be low, and a semiconductor display device having a photosensor and a display element formed over one substrate can be realized. In addition, a CMOS sensor requires lower driving voltage than a CCD sensor; therefore, power consumption of the solid-state imaging device can be suppressed.
For a solid-state imaging device or a semiconductor display device including a CMOS sensor, a rolling shutter method is generally employed in which an operation to accumulate charge in a photodiode and an operation to read the charge are sequentially performed row by row. However, in taking an image by a rolling shutter method, a period for performing accumulation operation in the first row differs from that in the last row. Thus, when an image of a fast-moving object is taken by a rolling shutter method, image data of the object with distortion is produced.
Patent Document 1 given below discloses a technique for correcting distortion of image data which occurs when an image is taken with a CMOS sensor by a rolling shutter method.